Intravascular blood pump and catheter

ABSTRACT

An intravascular system for pumping blood from a chamber of a heart and through an associated blood vessel coupled in fluid communication therewith. The system includes a pump device configured to be inserted into a blood vessel. The system further includes a catheter having a proximal end coupled to the pump device and a distal end configured to collect blood within or exiting from the chamber. The catheter further includes a pre-formed shape corresponding to the vessel to at least assist with stabilization and positioning of the pump device in the vessel.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Application Ser. No.12/396,048, filed Mar. 2, 2009, which is a continuation of PCTApplication Serial No. PCT/US2007/078507, filed Sep. 14, 2007 (expired)which claims the priority benefit of U.S. Provisional Patent ApplicationSer. No. 60/825,662, filed Sep. 14, 2006 (expired) and U.S. ProvisionalPatent Application Ser. No. 60/870,436, filed Dec. 18, 2006 (expired),the disclosures of which are incorporated by reference herein in theirentirety.

TECHNICAL FIELD

The present disclosure relates to vascular blood pump systems, and morespecifically, to an intravascular blood pump system for pumping bloodthrough an artery.

BACKGROUND

Intravascular blood pumps are a class of blood pumps or circulatoryassist devices that may be implanted into the vascular system (e.g., theveins or arteries) of a patient in either a percutaneous manner or asurgical manner. They may be used to assist the volume of blood beingejected from the left or right side of the heart. A particularintravascular pump is known generally as an axial flow blood pump andincludes a rotor or impeller surrounded by a protective housing. Thesecomponents (i.e., the pump, the rotor and housing) and any othercomponents connected therewith are coupled to the distal end of aflexible catheter. The catheter may be inserted into the vascularsystem, such as through generally remote access into a femoral artery.The catheter may ultimately be directed to and finally positioned in theascending aorta proximate to the left side of the heart, as one example.Rotational force on one or more impeller blades associated with theimplanted pump may be imparted by way of a mechanical connection anddrive or, for example, a magnetic connection and drive.

Despite the advances made in this area of blood pumps and systems, itremains desirable to provide improvements, for example, relatedgenerally to guiding, positioning, stabilizing and operatingintravascular blood pumps and systems incorporating such blood pumps.

SUMMARY

In an illustrative embodiment, an intravascular system for pumping bloodfrom a chamber of a heart and through an associated blood vessel coupledin fluid communication therewith is provided. The system includes a pumpdevice configured to be inserted into a blood vessel. The system furtherincludes a catheter having a proximal end coupled to the pump device anda distal end configured to collect blood within or exiting from thechamber. The catheter further includes a pre-formed shape correspondingto the vessel to at least assist with stabilization and positioning ofthe pump device in the vessel.

The catheter used in any of the embodiments encompassed herein mayfurther include first and second lumens. The first lumen is configuredto transport blood from the distal end to the proximal end and thesystem may further include a wire inserted into the second lumen andconfigured to define the pre-formed shape of the catheter. The cathetermay further include a helical portion, with the helical portion beingconfigured to facilitate securing the first end in the vessel. At leasta portion of the catheter may extend along an axis and the helicalportion may then extend around the axis generally parallel to a planetransverse to the axis. The catheter may further comprise a lumenextending from the distal end to the proximal end and at least one inletaperture into the lumen on the helical portion. The at least one inletaperture may be positioned generally to face the axis to minimizesuction with vascular walls.

Also in the various embodiments, the catheter may further includeradiopaque markers to facilitate positioning the catheter and the pumpdevice within the vascular system.

A lumen in the catheter may extend from the distal end to the proximalend with a guidewire entry port communicating with the lumen at thedistal end, and a guidewire exit port communicating with the lumen atthe proximal end.

A pump device is provided and is usable in connection with anyembodiment encompassed herein. The pump device includes a pump housinghaving a first end coupled to the catheter and a tubular body extendingfrom the first end along an axis. The tubular body includes an outersurface and at least one side outlet port extending through the outersurface. A pump is positioned within the tubular body of the pumphousing. A motor housing is also coupled to the pump housing, and amotor is positioned within the motor housing. The motor is configured tooperate the pump so that blood is drawn from the catheter, through thepump housing, and exits from the at least one side port.

In another embodiment, an intravascular pump device for pumping bloodfrom a catheter is provided and includes a pump housing having a firstend adapted to be coupled to the catheter, a second end, and a tubularbody extending between the first and second ends along an axis. A pumpis positioned within the tubular body of the pump housing. A motorhousing is coupled to the pump housing along the axis and is positionedproximate the second end. The motor housing has a diameter smaller thanthe tubular body such that the pump housing defines an outlet extendingalong the axis between the tubular body and the motor housing. A motoris positioned within the motor housing with the motor being configuredto operate the pump so that blood is drawn from the catheter, movesthrough the tubular body of the pump housing, and exits from the outlet.

With regard to the pump devices usable in connection with the othercomponents encompassed herein, a power cable may be coupled to the motorhousing along the axis or lengthwise direction of the tubular body. Themotor housing may include a tapered portion, for example, generallyalong the axis or lengthwise direction. The pump housing may be definedby a pump inlet housing coupled to the catheter and a pump outlethousing coupled to the motor housing. The pump outlet housing mayfurther include at least two vanes coupling the motor housing to thepump outlet housing.

Various additional features and aspects of the embodiments and scope ofthe invention will be more readily appreciated upon review of thefollowing detailed description of the illustrative embodiments taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view of one embodiment of a blood pump system.

FIG. 2 is a front elevational view of a pump device of the blood pumpsystem shown in FIG. 1.

FIG. 3 is a front elevational view of a portion of a catheter used inthe blood pump system of FIG. 1.

FIG. 4 is a side elevational view of a portion of the catheter shown inFIG. 4.

FIG. 5 is a perspective view of another embodiment of a blood pumpsystem.

FIG. 6 is a front elevational view of a pump device of the blood pumpsystem shown in FIG. 5.

FIG. 7 is a perspective view showing an outlet end of the pump deviceshown in FIG. 6.

FIG. 8 is an elevational view of another embodiment of a blood pumpsystem.

FIG. 9 is an enlarged view of the blood pump system shown in FIG. 8 andpartially fragmented to show internal portions of the inflow housing.

FIG. 10 is a further enlarged view of the blood pump and inflow sectionsshown in FIG. 9 and partially fragmented to show internal structure ofthe inflow housing and blood pump.

DETAILED DESCRIPTION

With reference to FIG. 1, one embodiment of an intravascular blood pumpsystem 10 is shown. The system generally includes a pump device 12, acatheter 14, and a pump cable 16 for supplying electrical power to thepump device 12. The system 10 is configured to be inserted into a bloodvessel, such as a vein or artery, to pump blood from within a chamber ofthe heart or at least a location close to an exit of a chamber, and thenthrough the associated vessel, as will be described in greater detailbelow.

As shown in FIGS. 1 and 2, the pump device 12 includes an elongate pumphousing 18 having a first end 20 coupled to a transition portion 22 ofthe catheter 14 and tubular body 24 extending from the first end 20along a longitudinal axis 26 of the pump housing 18. The first end 20may be secured to the transition portion 22 by rigid barbs, adhesive, orany other coupling technique. In one embodiment, the tubular body 24 isdefined by a pump inlet housing 28 and a pump outlet housing 30. Thepump inlet housing 28 and pump outlet housing 30 may secured together byinternal threads, adhesive, laser welding, or any other suitablecoupling technique. Various components of a blood pump are housed withinthe pump housing 18 to draw blood from the catheter 14 into the tubularbody 24. For example, the blood pump may comprise an impeller 33 andassociated impeller blades positioned within the pump inlet housing 28.A motor 35 positioned within a motor housing 32 proximate the pumpoutlet housing 30 rotates the impeller 33 to draw blood through thetubular body 24. It will be appreciated that the impeller 33 and motor35 are only schematically illustrated and may take many forms, includinga form as generally shown in FIGS. 9 and 10 herein.

The motor housing 32 may be sealingly coupled to the pump outlet housing30 and the transition portion 22 may be sealingly coupled to the pumpinlet housing 28 to help control the flow of blood within the tubularbody 24. One or more side outlet ports, slots, or apertures 34 extendthrough an outer surface 36 of the pump outlet housing 30 so that theblood drawn into the tubular body 24 through the catheter 14 by theblood pump may be delivered to the blood vessel, such as the vein orartery, into which the system 10 has been inserted. To eliminate sharpedges and to prevent areas of stagnant blood flow, the motor housing 32may be designed with a dome-shaped configuration as shown. The motorhousing 32 may also be configured to couple to the pump cable 16 alongthe longitudinal axis 26. Such an arrangement further reduces the amountof stagnation so as to minimize the formation of thrombus.

Referring to FIGS. 1, 3, and 4, the catheter 14 includes a proximal end40 (FIG. 1) coupled to the transition section 22, a distal end 42configured to collect blood exiting from a heart chamber, such as aventricle, and a lumen 14 a extending between the proximal and distalends 40, 42 within the catheter 14. More specifically, the distal end 42has a substantially linear portion 44 extending along an axis 46 and asubstantially helical portion 48 extending around the axis 46. Thehelical portion 48 first extends transverse to the axis 46 beforewrapping around it in a helical configuration generally parallel to aplane that is transverse to the axis 46. For example, the helicalportion 48 may include a transverse section 50 extending from thesubstantially linear portion 44 in a plane substantially perpendicularto the axis 46. The length of the transverse section 50 may varydepending upon the desired diameter of the helix formed by the helicalportion 48. The diameter of the helix is preferably large enough so thatouter surfaces 52 of the helical portion 48 contact or interact with thewalls of the blood vessel into which the catheter 14 is inserted. Suchan arrangement secures the catheter 14 within the blood vessel so thatit is stabilized and may not be easily retracted. The catheter 14 may bepre-formed with the desired shape so that the helical portion 48 retainsits helical configuration after the catheter's insertion, as will bedescribed below.

The helical portion 48 defines at least half of a full helix and mayhave a pitch greater than or equal to the outer diameter of the catheter14. Inlet apertures 54 positioned on inner surfaces 56 of the helicalportion 48 communicate with the lumen 14 a of the catheter 14. The inletapertures 54 may be circular, elliptical, triangular, or any othershape, and their cross-sectional areas may be greater than thecross-sectional area of the catheter lumen 14 a. The greatercross-sectional area allows blood to be freely drawn into and throughthe lumen 14 a when the pump device 12 is activated. This prevents bloodstagnation and the formation of thrombus outside of the lumen 14 a.Also, by virtue of the inlet apertures 54 being positioned on the innerwalls 56 and generally facing toward the axis 46, the catheter 14 avoidsa “suction effect” with adjacent vascular walls and structures when thepump device 12 is activated. In other words, the inlet apertures 54should not engage the vessel wall.

The catheter 14 and pump device 12 may be inserted into the blood vesselin a variety of ways. For example, in one embodiment the catheter 14includes a guidewire entry port 60 on a distal tip 72 and a guidewireexit port 62 proximate the transition section 22. After inserting aguidewire 63 into the blood vessel, the catheter 14 may be advanced overthe guidewire 63 until it is properly positioned. The guidewire 63 maythen be removed by retracting it through the guidewire exit port 62. Inan alternative embodiment, the catheter 14 may be inserted into theblood vessel through a sheath (not shown) and thus would not require theguidewire entry and exit ports 60, 62. A hydrophilic coating may beapplied to the catheters disclosed herein to facilitate insertion.Additionally, an anti-thromotic coating may also be applied to thecatheters to minimize the formation of thrombus.

The catheter 14 may be made from a variety of materials, including butnot limited to, silicone and polyurethane. The catheter 14 may also becomprised of a composite construction that incorporates a wire braid orcoil. As mentioned above, the catheter 14 may be pre-formed with a helixor other shape so that the helical portion 48 retains its shape afterinsertion. In other words, after the catheter 14 is manipulated andadvanced into the blood vessel in an expanded, non-helical form, orstraightened form, using a guidewire, sheath, or other insertiontechnique, the helical portion 48 can return to its pre-formed helicalshape upon removal of the guidewire, sheath, or other restraint. In oneembodiment, the catheter 14 is pre-formed with a helical configurationusing standard heat forming techniques. In another embodiment, thecatheter 14 incorporates a pre-formed NiTi or other shape memory wire ormaterial (not shown) for defining the helical shape. The wire may belocated in a separate, dedicated lumen or otherwise incorporated intothe catheter 14. Thus, in such an embodiment the catheter 14 has twolumens—one for delivering blood to the pump device and one for receivingthe NiTi wire.

The system 10 may be delivered to the vascular system using endovasculartechniques and may be designed to assist a particular heart chamber. Forexample, when designed to assist the right ventricle, the blood pumpdevice 12 may be subcutaneously inserted into the vena cava with thecatheter 14 extending toward the tricuspid valve. When designed toassist the left ventricle, the blood pump device 12 may besubcutaneously inserted into the descending aorta with the catheter 14extending toward the aortic valve. The pump device 12 may therefore besized to be received in a blood vessel of the vascular system. In oneembodiment, the pump housing 18 has an outer diameter of approximately13 mm.

Properly positioning the system 10 within the vascular system can be asignificant challenge due to bends and convolutions of the various bloodvessels. To address these challenges, the catheter 14 may be constructedwith a combination of appropriately sized straight sections 44, 64, 65and curved sections 66. For example, the curved section 66 may bedesigned to reflect the curvature of the aortic arch if the system isused to assist the left ventricle. Additionally, the length of thesection 65 at the proximal end 40 may be selected to be a short distanceto position the pump device 12 immediately proximate the curved section66 within the blood vessel (such as the aorta with the curved section 66corresponding to a location near the aortic arch) or a longer distanceto position the pump device 12 proximate the endovascular entry site(typically the femoral artery) above bifurcation in the iliac artery.The shapes of the various catheter sections 44, 64, 65, 66 are similarto those of guiding catheters used for coronary access. The cathetersections may also be pre-formed to desired shapes using the sametechniques discussed above with respect to the helical portion 48.

To further assist positioning within the vascular system, the catheter14 may include one or more radiopaque bands 70 at desired locationsalong the catheter 14. FIGS. 1 and 3 illustrate two radiopaque bands 70on the substantially linear portion 44 of the distal end 42. The distalend 42 may also be provided with a radiopaque tip 72 to furtherfacilitate positioning the system relative to an anatomical landmarksuch as the aortic or tricuspid valve.

Now referring to FIGS. 5-7, an intravascular blood pump system 110according to a second embodiment is shown. The system 110 includes thesame catheter 14 and pump cable 16 as the system 10. Because referencecan be made to the description of these components in FIGS. 1-4, onlythe differences between the systems 10 and 110 will be described indetail.

The system 110 includes a pump device 112 having an elongate pumphousing 118 with a first end 120 coupled to the transition section 22 ofthe catheter 14. A tubular body 124 extends from the first end 120 alongan axis 126 and terminates at a second end 128. In one embodiment, apump inlet housing 130 and a pump outlet housing 132 define the tubularbody 124. The tubular body 124 houses the various components of a pump,such as shown in FIGS. 8-10 and described further below. A motor (notshown) positioned within a motor housing 134 drives the components ofthe pump to draw blood into and through the tubular body 124.

Instead of incorporating side ports for blood to exit the pump device112, the pump housing 118 defines an opening or outlet 140 at the secondend 128. Although the motor housing 134 is positioned proximate thesecond end 128, the motor housing 134 has a smaller diameter than theoutlet 140 so that the impeller blades may pump blood out of the pumpdevice 12 and into the blood vessel. The motor housing 134 may bedesigned with a tapered portion as shown to prevent abrupt changes inblood flow and minimize areas of stagnation. This coaxial arrangement ofthe pump and outlet 140 allows the pump device 112 to be positionedadjacent the wall of the blood vessel without imposing a direct fluidforce against the wall.

As shown in FIG. 7, the motor housing 134 may be coupled to the pumphousing 118 by vanes 144. The device 112 preferably incorporates atleast two vanes 144 to secure the motor housing 134 during operation.The vanes 144 have contours designed to minimize their disruption of theblood flow through the tubular body 124. Additionally, radii areprovided where the vanes 144 couple to the motor housing 134 and pumphousing 118 to minimize thrombus formation and any potential damage tothe blood flowing through the tubular body.

FIGS. 8-10 illustrate a blood pump system 160 according to a thirdembodiment. The system 160 includes a pump device 162 receiving powerfrom a suitable cable 164 in the form of a catheter device that may beinserted through the vascular system of the patient. The pump 162 isconnected to a distal catheter portion 166 having a blood inflow tip168. Catheter portion 166 may have a preformed, angled shape as shown.The blood inflow tip 168 includes suitable openings 168 a for allowingblood to be drawn into the tip portion 166. A blood outflow or exit 170is provided adjacent to the pump 162. Referring more specifically toFIGS. 9 and 10, the blood outflow comprises openings 170 adjacent to apump rotor 172 that is magnetically coupled to the rotating output 174of the pump motor 176. The pump motor 176 is therefore completely sealedand respective permanent magnets carried on the pump rotor 172 and therotating output 174 transfer rotation from the output 174 to the rotor172 which is supported for rotation in the inflow housing 180. In onesuitable use of system 160, the intravascular pump 162 may reside in apatient's aorta, with tip portion 166 extending through the aortic valvesuch that the inflow tip 168 resides within the left ventricle of thepatient. Blood would therefore be drawn from the ventricle into theinflow tip 168 through openings 168 a, then travel through tip portion166 and exit at the outflow openings 170 into the patient's aorta. Thiswould assist with expelling blood from the patient's left ventricle.

While the present invention has been illustrated by a description ofvarious illustrative embodiments and while these embodiments have beendescribed in some detail, it is not the intention of the Applicants torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. The various features of the invention may beused alone or in any combination depending on the needs and preferencesof the user. This has been a description of the present invention, alongwith the preferred methods of practicing the present invention ascurrently known. However, the invention itself should only be defined bythe appended claims. What is claimed is:

1. An intravascular pump device for pumping blood from a catheter,comprising: a pump housing having a first end adapted to be coupled tothe catheter, a second end, and a tubular body extending between saidfirst and second ends along an axis; a pump positioned within saidtubular body of said pump housing; a motor housing coupled to said pumphousing along said axis and positioned proximate said second end, saidmotor housing having a diameter smaller than said tubular body such thatsaid pump housing defines an outlet extending along said axis betweensaid tubular body and said motor housing; and a motor positioned withinsaid motor housing, said motor being configured to operate said pump sothat blood is drawn from said catheter, moves through said tubular bodyof said pump housing, and exits from said outlet.
 2. The pump device ofclaim 1, further comprising: a power cable coupled to said motor housingalong said axis.
 3. The pump device of claim 1, wherein said motorhousing has a tapered portion.
 4. The pump device of claim 1, whereinsaid pump housing is defined by a pump inlet housing coupled to thecatheter and a pump outlet housing coupled to said motor housing.
 5. Thepump device of claim 4, wherein said pump outlet housing furtherincludes at least two vanes coupling said motor housing to said pumpoutlet housing.
 6. An intravascular pump device for pumping blood from acatheter, comprising a pump housing having a first end coupled to saidcatheter, a second end, and a tubular body extending between said firstand second ends along an axis, said tubular body having an outer surfaceand at least one side outlet port extending through said outer surface;a pump positioned within said tubular body of said pump housing andincluding an impeller, said impeller spaced axially from said at leastone side outlet port; a motor housing coupled to said pump housing alongsaid axis and positioned proximate said second end; and a motorpositioned within said motor housing, said motor being configured tooperate said pump so that blood is drawn from said catheter, throughsaid pump housing, exits from said at least one side outlet port, and isdirected into a vessel into which the pump device has been inserted. 7.The system of claim 6, wherein said motor housing has a dome-shapedportion extending along said axis, said dome-shaped portion beingconfigured to prevent areas of stagnant blood flow.
 8. The pump deviceof claim 6, further comprising: a power cable coupled to said motorhousing along said axis.
 9. An intravascular pump device for pumpingblood from a catheter, comprising: a pump housing having a first endadapted to be coupled to the catheter, a second end, and a tubular bodyextending between said first and second ends along an axis, said pumphousing being defined by a pump inlet housing coupled to said catheteron one end of the pump inlet housing, and a pump outlet housing coupledto another end of the pump inlet housing; at least one outlet positionedon or at said pump outlet housing; a pump positioned within said tubularbody of said pump housing and including an impeller, said impellerspaced axially from said at least one side outlet port; a motor housingcoupled to said pump housing along said axis and positioned proximatesaid second end, a motor positioned within said motor housing, saidmotor being configured to operate said pump so that blood is drawn fromsaid catheter, moves through said tubular body of said pump housing,exits from said outlet, and is directed into a vessel into which thepump device has been inserted.